Dohuk: The president of Iraq`s autonomous region of Kurdistan, Massud Barzani, promised Monday to avenge the Yazidi minority brutally attacked by the Islamic State group a year ago.

"We will hunt down those who committed this crime until the last one," Barzani said in Dohuk at a ceremony commemorating the beginning of the jihadist onslaught against the Yazidis.

A Kurdish-speaking minority mostly based around the Sinjar mountain in northern Iraq, the Yazidis are neither Arabs nor Muslims and have a unique faith IS considers to be polytheism.

On August 3 last year, the jihadists made an unexpected push into areas of northern Iraq that had been under Kurdish control and were home to many of the country`s minorities.

The worst-hit were the Yazidis, who were massacred and abducted in large numbers when IS entered the Sinjar area.

Tens of thousands of them scrambled up Mount Sinjar in a panic and remained stranded there for days with no food nor water in searing summer temperatures.

Dramatic footage of their flight through Syria and back into autonomous Iraqi Kurdistan caught the world`s attention.

The jihadist onslaught against the Yazidis has been described by the United Nations as "an attempt to commit genocide" and was one of the main justifications for the US-led air campaign against IS that began days later.

Backed by the international coalition that subsequently developed, the Kurdish peshmerga as well as Kurdish forces from neighbouring Syria have clawed back land, but not all of it.

"They (IS) have left thousands of bodies on the battlefield, but this is not enough in comparison with the crimes they committed," Barzani said.

The Kurdistan Regional Government (KRG) released figures on the Yazidis claiming that the community counts 550,000 members in Iraq.

The figures said Yazidis account for 400,000 of the more than three million people who have been displaced in Iraq since violence erupted at the beginning of 2014.

According to the KRG figures, 1,280 Yazidis were killed in the IS offensive, 280 died due to the conditions they were subjected to and 841 are still missing.

More than 5,800 were also abducted by IS, which has used Yazidi girls and women as slaves. Just over 2,000 of them have managed to flee, the KRG said.